The problem of fault diagnosis has been widely discussed by the academic community using the theory of Discrete Event Systems. However, the application of this theory to real systems is a field where there is a lot to be explored. The problem proposed in this work is to diagnose permanent or intermittent failures in devices (sensors and actuators) belonging to stations of a didactic flexible manufacturing system, called Modular Production System - MPS, produced by Festo company. The objective will be achieved through a modeling and simulation that allow for future implementation in the system. Three methods will be presented on fault diagnosis written in UPPAAL software language which is based on the timed safety automata formalism, as proposed by ALUR and DILL (1994) and HENZINGER et al (1994). The first method is an implementation of TRIPAKIS (2002) diagnoser. The other two methods developed in this research are inspired by TRIPAKIS (2002) and are diagnosable by definitions presented in TRIPAKIS (2002) and I-diagnosability presented in Sampath et al. (1995). The strategies for fault detection include the use of a network of timed safety automata, composed of the automaton that describes the process behavior and the diagnosers automata for each type of failure. The diagnosers detect failures from the observation of delays of certain transitions in the automaton G (process) and isolate them through observations of the sensors states. Fault indicators events serve to announce failures and synchronize the automaton G with the diagnosers. / O problema do diagnóstico de falhas, utilizando a teoria de Sistemas a Eventos Discretos, tem sido largamente abordado pela comunidade acadêmica. Entretanto, a aplicação desta teoria a sistemas reais é um campo onde há muito a ser explorado. O problema proposto, neste trabalho, é o de diagnosticar falhas permanentes ou intermitentes de dispositivos (sensores e atuadores) pertencentes a estações de um sistema flexível de manufatura didático, denominado Sistema Modular de Produção - MPS, fabricado pela empresa Festo. Este objetivo será alcançado por meio de uma modelagem e simulação que permitam uma futura implementação no sistema. Serão apresentados três métodos para diagnóstico de falhas escritos na linguagem do software UPPAAL que se baseia no formalismo autômatos seguros temporizados, conforme proposto por ALUR e DILL (1994) e HENZINGER et al (1994). O primeiro método é uma implementação do diagnosticador proposto em TRIPAKIS (2002). Os outros dois métodos, elaborados nesta pesquisa, são inspirados no diagnosticador TRIPAKIS (2002) e são diagnosticáveis pelos critérios apresentados em TRIPAKIS (2002) e Idiagnosticabilidade conforme SAMPATH et al. (1995). As estratégias para detecção de falhas incluem a utilização de uma rede de autômatos seguros temporizados, composta pelo autômato que descreve o comportamento do processo e por autômatos diagnosticadores para cada tipo de falha. Os diagnosticadores detectam as falhas a partir da observação de atrasos de determinadas transições do autômato G (processo) e as isolam por meio de observações dos estados dos sensores. Eventos indicadores de falhas servem para anunciar falhas e sincronizar o autômato G com os diagnosticadores.

Cette thèse a pour objectif la génération de séquences de franchissement dans les Réseaux de Petri Temporisés (RdPT) en utilisant une approche incrémentale. Le verrou principal auquel est confronté ce travail est l’explosion combinatoire qui résulte de la construction classique du graphe d’accessibilité du RdPT. Nous proposons d’utiliser la notion de séquence de steps temporisés, afin d’exprimer progressivement l’ensemble des séquences de franchissements permettant de passer d’un état courant à un état cible. La notion de step temporisé correspond à une abstraction logique du comportement du système considéré. Le caractère incrémental de l’approche a pour objectif de gagner en efficacité. En effet, il consiste à exprimer tout nouvel état de la résolution par rapport à une profondeur K+1, en fonction d’un état atteint à la profondeur K. Ainsi, nous proposons plusieurs algorithmes de recherche incrémentale permettant d'améliorer l'efficacité de la résolution des problèmes d'accessibilité. Nous utilisons ensuite la programmation par contraintes pour modéliser le problème de recherche d’accessibilité dans un RdPT et mettre en œuvre notre approche incrémentale. Notre approche permet également d’ajouter des contraintes spécifiques à un contexte de résolution. Nous avons notamment utilisé cette possibilité pour proposer des techniques d'identification des jetons dans un RdPT borné, dans le cadre de la reconfiguration des systèmes manufacturiers. Nous concluons par l’évaluation de différentes applications constituant des « benchmarks » permettant d’illustrer l'efficacité des approches proposées / This PhD thesis is dedicated to the generation of firing sequences in Timed Petri Net (TPN) using an incremental approach. To reduce the influence of the well-known combinatorial explosion issue, a unique sequence of timed steps is introduced to represent implicitly the underlying reachability graph of the TPN, without needing its whole construction. This sequence of timed steps is developed based on the logical abstraction technique. The advantage of the incremental approach is that it can express any state just from the last step information, instead of representing all states before.Several incremental search algorithms are introduced to improve the efficiency of our methodology. Constraint programming techniques are used to model and solve our incremental model, in which search strategies are developed that can search for solutions more efficiently. Our methodology can be used to add specific constraints to model realistic systems. Token identification techniques are developed to handle token confusion issues that appear when addressing the reconfiguration of manufacturing systems. Experimental benchmarks illustrate the effectiveness of approaches proposed in this thesis

Bibliographic identification IŠTOKOVÁ, Lucie. The influence of cochlear implant on vestibular function in adult patients. Prague: Charles University, 2nd Faculty of Medicine, Department of Rehabilitation and Sports Medicine, 2020. 58 p., Appendices. Thesis supervisor Mgr. Klára Kučerová. Abstract Severe hearing loss is standardly treated by cochlear implantation. Considering the anatomical proximity and interconnection to the vestibulocochlear nerve, it is possible to influence vestibular functions. The aim of this diploma thesis is to evaluate the effect of unilateral cochlear implantation on postural stability and vestibular function in adult patients with severe hearing loss caused postlingually. Eleven patients aged 28-72 were examined the day before surgery, the day after surgery, and on average 25 days after surgery. The evaluation consisted of short-form Dizziness Handicap Inventory (DHI), Timed Up and Go testing (TUG), static stabilometry and the perception of the subjective visual vertical (SVV) static and dynamic. Significant deterioration of TUG and SVV was recorded particularly immediately after surgery. In dynamic SVV, especially, when the field of view rotated to the left. Considerable results in stabilometry were only when standing on a hard surface with eyes closed. Improvements in TUG, SVV...

Modern information technology increases the use of computers in training systems as well as in command-and-control systems in military services and public-safety organizations. This computerization combined with new threats present a challenging complexity. Situational awareness in evolving distributed operations and follow-up in training systems depends on humans in the field reporting observations of events. The use of this observer-reported information can be largely improved by implementation of models supporting both reporting and computer representation of objects and phenomena in operations. This thesis characterises and describes observer model-based data collection in distributed tactical operations, where multiple, dispersed units work to achieve common goals. Reconstruction and exploration of multimedia representations of operations is becoming an established means for supporting taskforce training. We explore how modelling of operational processes and entities can support observer data collection and increase information content in mission histories. We use realistic exercises for testing developed models, methods and tools for observer data collection and transfer results to live operations. The main contribution of this thesis is the systematic description of the model-based approach to using observers for data collection. Methodological aspects in using humans to collect data to be used in information systems, and also modelling aspects for phenomena occurring in emergency response and communication areas contribute to the body of research. We describe a general methodology for using human observers to collect adequate data for use in information systems. In addition, we describe methods and tools to collect data on the chain of medical attendance in emergency response exercises, and on command-and-control processes in several domains.

ROS2 is an increasingly popular middleware framework for developing robotic applications. A ROS2 applicationbasically is composed of nodes that run concurrently and can be deployed distributedly. ROS2 nodes communicatewith each other through asynchronous interfaces; they reside in memory and wait to respond events that circulatearound the system during the interactions between the robot(s) and the environment. Rebeca is an actor-basedlanguage for modelling asynchronous, concurrent applications. Timed Rebeca added timing features to Rebeca todeal with timing requirements of real-time systems. The similarities in the concurrency and message-basedasynchronous interactions ofreactive nodes justify the relevance of using Timed Rebeca to assist the developmentand verification of ROS2 applications. Model-based development and model checking allow quicker prototypingand earlier detection ofsystem errors without the requirement of developing the entire real system. However, thereare challenges in bridging the gaps between continuous behaviours in a real robotic system and discrete behavioursin a model, between complex computations in a robotic system and the inequivalent programming facilities in amodelling language. There have been previous attempts in mapping Rebeca to ROS, however they could not beput into practice due to over-simplifications or improper modelling approaches. This thesis addresses the problemfrom a more systematic perspective and has been successful in modelling a realistic multiple autonomous mobilerobots system, creating corresponding ROS2 demonstration code, showing the synchronization between the modeland the program to prove the values of the model in driving development and automatic verification of correctnessproperties (freedom ofdeadlocks, collisions, and congestions). Stability of model checking results confirms designproblems that are not always detected by simulation. The modelling principles, modelling and implementingtechniques that are invented and summarized in this work can be reused for many other cases.

One of the most significant urban transport problems is traffic congestion. All major cities both in developed and developing countries are facing the problem due to increasing travel demand caused by increasing urbanization and the attendant economic and population growth. Recognizing the growing burden of traffic congestion, community leaders and transportation planners in Addis Ababa are still actively promoting large-scale road constructions to alleviate traffic congestion. Although Intelligent Transportation Systems(ITS) applications seem to have the potential to improve signalization performance, highly congested intersections in Addis Ababa are still controlled by a timed signal and manual operation. Moreover, these pre-timed signal controls are functioning sub-optimally as they are not being regularly monitored and updated to cope with varying traffic demands. Even though the benefits are well known theoretically, at the time of writing of this thesis, Adaptive Traffic Signal Controllers (ATSC) haven’t been deployed in Ethiopia and no research has been conducted to demonstrate and quantify their effectiveness. This master’s research thesis, therefore, intends to fill the identified gap, by undertaking a microscopic traffic simulation investigation, to evaluate the benefits of adopting a Traffic-responsive Urban Control (TUC) strategy and optimizing traffic signal timings. For the purpose of this study, an oversaturated three-intersection test corridor located in the heart of Addis Ababa city is modeled in VISSIM using real-world traffic data. After validating the calibrated model, the corridor was evaluated with the existing pre-timed, TRANSYT optimized pre-timed plan and TUC strategy. Multiple simulation runs were then made for each scenario alternatives and various measures of effectiveness were considered in the evaluation process. Simulation evaluation has demonstrated an average delay reduction of 24.17% when the existing pre-timed alternative is compared to TRANSYT optimized plan and 35% when compared to the TUC strategy. Overall evaluation results indicate that deploying the TUC strategy and optimizing the aging pre-timed signal plans exhibits a significant flow improvement. It is expected that the result of the thesis work will be an input for future comprehensive policy development processes.

Since 2009, Moving Target Defense (MTD) has become a new paradigm of defensive mechanism that frequently changes the state of the target system to confuse the attacker. This frequent change is costly and leads to a trade-off between misleading the attacker and disrupting the quality of service. Optimizing the MTD activation frequency is necessary to develop this defense mechanism when facing realistic, multi-step attack scenarios. Attack modeling formalisms based on DAG are prominently used to specify these scenarios. It represents the attack goal in the root of a tree that is recursively refined into subgoals to show the different ways the attacker can compromise the system. According to some specific models, the tree is augmented with countermeasures, time, costs, or probabilities. Our contribution is a new DAG-based formalism for MTDs and its translation into a Price Timed Markov Decision Process to find the best activation frequencies against the attacker’s time/cost-optimal strategies. For the first time, MTD activation frequencies are analyzed in a state-of-the-art DAG-based representation. Moreover, this is the first paper that considers the specificity of MTDs in the automatic analysis of attack modeling formalisms. Finally, we present some experimental results using UPPAAL STRATEGO to demonstrate its applicability and relevance. / Sedan 2009 har Moving Target Defense (MTD) blivit ett nytt paradigm av defensiv mekanism som ofta ändrar målsystemets tillstånd för att förvirra angriparen. Denna frekventa förändring är kostsam och leder till en avvägning mellan att vilseleda angriparen och att störa målsystemets tillförlitlighet. Att optimera MTD-aktiveringsfrekvensen är nödvändigt för att utveckla denna försvarsmekanism när man står inför realistiska attackscenarier i flera steg. Attackmodelleringsformalismer baserade på DAG är de främst använda metoderna för att specificera dessa scenarier. Metoden representer attackmålet i roten av ett träd som rekursivt förfinas till delmål för att visa de olika sätt som angriparen kan äventyra systemet. Enligt vissa specifika modeller är trädet utökat med motåtgärder, tid, kostnader eller sannolikheter. Vårt bidrag är en ny DAG-baserad formalism för MTD:er och dess översättning till en Price Timed Markov Decision Process för att hitta de bästa aktiveringsfrekvenserna mot angriparens tids-/kostnadsoptimala strategier. För första gången analyseras MTD-aktiveringsfrekvenser i en toppmodern DAG-baserad representation. Dessutom är detta det första rapporten som överväger specificiteten hos MTD:er i den automatiska analysen av attackmodelleringsformalismer. Slutligen presenterar vi några experimentella resultat med UPPAAL STRATEGO för att visa dess tillämpbarhet och relevans.

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京都大学 / 新制・課程博士 / 博士(医学) / 甲第24135号 / 医博第4875号 / 新制||医||1060(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 近藤 尚己, 教授 川上 浩司, 教授 阪上 優 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

In the area of Discrete Event Systems (DES), formal verification techniques are important in examining a variety of system properties including controllability and nonblocking. Nonetheless, in reality, most software and hardware practitioners are not proficient in formal methods which holds them back from the formal representation and verification of their systems. Alternatively, it is a common observation that control engineers are typically familiar with Moore synchronous Finite State Machines (FSM) and use them to express their controllers’ behaviour. Taking this into consideration, we devise a generic and structured approach to automatically translate Moore synchronous FSM into timed DES (TDES) supervisors. In this thesis, we describe our FSM-TDES translation method, present a set of algorithms to realize the translation steps and rules, and demonstrate the application and correctness of our translation approach with the help of an example. In order to develop our automatic FSM-TDES translation approach, we exploit the structural similarity created by the sampled-data (SD) supervisory control theory between the two models. To build upon the SD framework, first we address a related issue of disabling the tick event in order to force an eligible prohibitable event in the SD framework. To do this, we introduce a new synchronization operator called the SD synchronous product (||SD), adapt the existing TDES and SD properties, and devise our ||SD setting. We formally verify the controllability and nonblocking properties of our ||SD setting by establishing logical equivalence between the existing SD setting and our ||SD setting. We present algorithms to implement our ||SD setting in the DES research tool, DESpot. The formulation of the ||SD operator provides twofold benefits. First, it simplifies the design logic of the TDES supervisors that are modelled in the SD framework. This results in improving the ease of manually designing SD controllable TDES supervisors, and reduced verification time of the closed-loop system. We demonstrate these benefits by applying our ||SD setting to an example system. Second, it bridges the gap between theoretical supervisors and physical controllers with respect to event forcing. This makes our FSM-TDES translation approach relatively uncomplicated. Our automatic FSM-TDES translation approach enables the designers to obtain a formal representation of their controllers without designing TDES supervisors by hand and without requiring formal methods expertise. Overall, this work should increase the adoption of the SD supervisory control theory in particular, and formal methods in general, in the industry by facilitating software and hardware practitioners in the formal representation and verification of their control systems. / Dissertation / Doctor of Philosophy (PhD)